An Immunohematology Reference Center is proposed to meet the increasing needs for seeological reagents that identify the Canine red cell antigens (blood groups) and histocompatibility antigens. A colony of dogs currently exist that produce the reagents that recognize the red cell atigens. The center will maintain and expand this national resource, providing reagents and typing services to qualified investigators of multiple disciplines, that require a more completely characterized animal model for the study of transplantation immunology, coagulation deficiency states, tumor immunology, immunohematological problems and immunopathological conditions. The center will serve as a focus for collaboration with natonal and international investigators that are studying the major histocompatibility complex of the canine. This will aid in the standardization of test and notation systems. The specific aims of the center are compatible with the program statement of the Laboratory Animal Science Program of the Animal Resources Branch and supportive to the program guidelines of the National Advisory, Heart and Lung Council,"Special Animal Models Resources for Thrombotic and Hemorrhagic Disorders". BIBLIOGRAPHIC REFERENCES: Bull, R. W., Vriesendorp, H.M., Zwiebaum, A., Swisher, S.N., l975: The inapplicability of CEA-7 as a canine bone marrow transplantation marker. Transplantation Proceedings. 7(4): 575-577. Anderson, L.K., Keller, W., Blanchard, G.L., Bull, R.W., l975: Serum and lacrimal immunoglobulins in normal German Shepherds and German Shepherds with Pannus. Proceedings of the American Society of Veterinary Ophthmalogists.